Table 3.

Risk of death or hospitalization associated with randomization to digoxin stratified by improvement in renal function status, in the subgroup of patients with one year serum digoxin levels ≤0.8 ng/ml.

	No IRF		Yes IRF		p interaction
	HR (95% CI)	p	HR (95% CI)	p
Death or Hospitalization
(n events = 305)
Unadjusted	0.86 (0.66–1.1)	0.277	0.46 (0.25–0.82)	0.010*	0.054*
Adjusted for baseline eGFR	0.95 (0.72–1.2)	0.676	0.41 (0.24–0.80)	0.007*	0.023*
Adjusted for 12 month eGFR	0.97 (0.74–1.3)	0.827	0.42 (0.23–0.77)	0.005*	0.014*
Adjusted for baseline Characteristics	0.92 (0.70–1.2)	0.524	0.30 (0.16–0.58)	<0.001*	0.018*
Death (n events = 190)
Unadjusted	0.84 (0.60–1.2)	0.316	0.37 (0.16–0.84)	0.017*	0.066*
Adjusted for baseline eGFR	0.91 (0.65–1.3)	0.576	0.36 (0.16–0.82)	0.015*	0.042*
Adjusted for 12 month eGFR	0.96 (0.68–1.3)	0.807	0.36 (0.16–0.81)	0.014*	0.029*
Adjusted for baseline characteristics	0.93 (0.66–1.3)	0.662	0.35 (0.15–0.79)	0.012*	0.023*
Hospitalization (n events = 208)
Unadjusted	0.86 (0.62–1.2)	0.354	0.58 (0.29–1.1)	0.112	0.301
Adjusted for baseline eGFR	0.95 (0.69–1.3)	0.755	0.54 (0.28–1.1)	0.079	0.164
Adjusted for 12 month eGFR	0.98 (0.71–1.4)	0.891	0.52 (0.26–1.0)	0.060	0.120
Adjusted for baseline characteristics	0.88 (0.64–1.2)	0.456	0.38 (0.17–0.82)	0.014*	0.145

Improvement in renal function (IRF) defined as a ≥20% increase in estimated globular filtration rate (eGFR) from randomization to one year. Patients in the placebo group were assumed to have a serum digoxin level less than 0.8 ng/ml. Baseline characteristics adjusted for: age, race, ejection fraction, heart rate, systolic blood pressure, NHYA class, diabetes mellitus, baseline use of digoxin, hydralazine, nitrates, diuretics, or angiotensin converting enzyme inhibitors, physical examination findings, cardio-thoracic ratio, and baseline eGFR.

^*Significant p value.